1. Field of the Invention
The present invention relates to an automatic automotive transmission and more specifically to such a transmission which includes an arrangement for attenuating select shock when the transmission is conditioned to produce reverse gear
2. Description of the Prior Art
Nissan Motor Automatic Transaxle RN4FO2A and RL4FO2A (A261C06) discloses on pages 55 and 56 an arrangement wherein a reverse clutch (or rear clutch as it is sometimes referred to) and a low and reverse brake are arranged in the manner shown in FIG. 1. This arrangement however, has suffered from the drawback that, due to the difference in stroke lengths of the two friction elements and the length and the flow resistance of the conduits associated therewith, the reverse clutch engages before the low and reverse brake. This results in a two stage or double select shock being produced.
That is to say, when the reverse clutch is engaged the input shaft becomes connected with the sun gear of the left-hand or first planetary gear unit 101 (as seen in the drawings). However, as the carrier 102 of the gear unit 101 is not braked at this time it tends also to rotate. The inertia of these elements produces a first shock. Following this, the engagement of the low and reverse brake stops the rotation of the carrier 102 of the planetary gear unit 101 which is induced by the prior engagement of the reverse clutch and induces a second inertia related shock.